Dynamo electric machines

ABSTRACT

A dynamo electric machine having a wound rotor and a commutator rotatable with the rotor. The conductors of the rotor are in pairs each pair being connected electrically to a respective commutator segment. One end of one conductor of each pair is electrically and physically connected to the other conductor and a projecting portion of said other conductor is electrically connected to the commuator segment.

C United States Patent 1 3,665,233 Bowcott {451 May 23, 1972 54 DYNAMQELECTRIC MACHINES 2,884,749 7/ I958 Shetterly 29/597 3,568,309 3/1971Preece 310/234 1 Invwwfl m M Sohhull, Enalmd 3,522,462 8/1970 Schwartz....310/234 73 m y l m m Bib 3,145,260 8/1964 Reid 339/244 mingham,England D Ml Primary Examiner-J. er m1 Assistant ExaminerR. Skudy [2|]Appl.No.: 83,223 Atromey-Holman&Stern Related US. Application Dela 57ABSTRACT [62] of 1969' aban A dynamo electric machine having a woundrotor and a commutator rotatable with the rotor. 'lhe conductors of therotor are in pairs each pair being connected electrically to a respecgftive commutator segment. One end of one conductor of each I 1 pair iselectrically and physically connected to the other con- [58]FleldnlSenreh ..3 10/234, 233, 236, 237,

29/597 339,244 ductor and a projecting portion of said other conductorIS electrically connected to the commuator segment. [561 Mm CM!4Clnhm,5Drawlng Figures UNITED STATES PATENTS I VII PATENTEU MAY 2 31972 SHEET 1 [IF 2 PATENTinmzsmz SHEET 2 UP 2 Lff/ DYNAMO ELECTRICMACHINES This invention relates to dynamo electric machines and isdivided from my copending application Ser. No. 797,457 filed Feb. 7,1969, now abandoned.

A dynamo electric machine according to the invention includes a woundrotor and a commutator rotatable with the rotor, the conductors of therotor being electrically connected in pairs to the segments of thecommutator, one end of one conductor of each pair of conductors beingelectrically and physically connected to the respective segment and theone end of the other conductor of the pair of conductors beingelectrically and physically connected to said one conductor adjacent thesegment.

One example of the invention is illustrated in the accompanying drawingswherein:

FIGS. 1 to 4 illustrate four stages in the connection of rotorconductors of a dynamo electric machine to the commutator thereof, and

FIG. 5 is a sectional view of part of the completed machine.

In the example to be described, a dynamo electric machine (FIG. 5)includes a rotor 8 having a rotor assembly carrying windings 9 and aface type commutator 10 to which the windings 9 of the rotor assemblyare to be electrically connected. The windings 9 of the rotor assemblyare formed from copper strip and the arrangement is such that the endsof pairs of windings are to be electrically connected to respectivesingle segments of the commutator 10. The segments of the commutator 10includes respective integral risers to which the windings are to beelectrically connected.

The pairs of windings are connected to their respective segments in thefollowing manner.

Two conductors 11,12 of the winding 9 are led from the rotor assemblytowards the commutator 10 and are resistance welded to one anotheradjacent the commutator using a pair of electrodes 13,14 (FIG. 1 Thefree end of the conductor 12, at the side of the weld remote from therotor assembly, is severed so that the conductor 1 1 is longer than theconductor 12 as shown in FIG. 2. The free end of the longer conductor 11is then inserted into a slot 15 in the riser 16 of the respectivecommutator segment as shown in FIG. 3, and the arrangement is such thatwhen the end of the longer conductor 11 is housed in the slot 15, thefree end of the shorter conductor 12 lies adjacent the rear face of theriser 16.

The riser is then subjected to a hot staking process to deform the wallof the slot in the riser, in a manner to trap the free end of theconductor 11 in the slot, and to electrically interconnect the riser 16and the conductor 11. The hot staking process is carried out by engagingan electrode 17 with the face of the riser, and engaging a secondelectrode 18 with the top of the riser adjacent the open end of the slotas shown in FIG. 3. An electric current is then passed between theelectrodes 17,18 which causes the portion of the riser between theelectrodes to become heated, whereupon the second electrode is used as apress tool to deform the walls of the slot in the riser. In this way,the segment is electrically connected through its riser to the longerconductor 11 and through the free end of the longer conductor 1 1 to theshorter conductor 12. Moreover, the deformation of the riser physicallyconnects the end of the longer conductor 11 to the commutator, so thatboth conductors 11,12 are held in place relative to the com mutator. Theother pairs of conductors are connected to their respective segments insimilar manner.

It will be appreciated that windings can be secured to either barrel orface commutators in the manner described above.

Having thus described my invention what 1 claim as new and desire tosecure by Letters Patent is:

1. A dynamo electric machine including a wound rotor and a commutatorrotatable with the rotor, the conductors of the rotor being electricallyconnected in pairs to the segments of the commutator, one end of oneconductor of each pair of conductors being electrically and physicallyconnected to the respective commutator segment and the one end of theother conductor of the pair of conductors terminating short of thecommutator segment and being electrically and physically connected tosaid one conductor adjacent the segment, so as to be electricallyconnected to the segment through said one conductor.

2. A dynamo electric machine as claimed in claim 1 wherein thecommutator is a face type commutator.

3. A dynamo electric machine as claimed in claim 1 wherein said otherconductor is welded to said one conductor adjacent the end of said oneconductor, the end of said one conductor projecting beyond the end ofsaid other conductor.

4. A dynamo electric machine as claimed in claim 1 wherein said oneconductor is physically and electrically connected to the respectivecommutator segment by engaging the end of said one conductor in a slotin said one segment and then hot staking the segment to connect thesegment to the conductor.

1. A dynamo electric machine including a wound rotor and a commutatorrotatable with the rotor, the conductors of the rotor being electricallyconnected in pairs to the segments of the commutator, one end of oneconductor of each pair of conductors being electrically and physicallyconnected to the respective commutator segment and the one end of theother conductor of the pair of conductors terminating short of thecommutator segment and being electrically and physically connected tosaid one conductor adjacent the segment, so as to be electricallyconnected to the segment through said one conductor.
 2. A dynamoelectric machine as claimed in claim 1 wherein the commutator is a facetype commutator.
 3. A dynamo electric machine as claimed in claim 1wherein said other conductor is welded to said one conductor adjacentthe end of said one conductor, the end of said one conductor projectingbeyond the end of said other conductor.
 4. A dynamo electric machine asclaimed in claim 1 wherein said one conductor is physically andelectrically connected to the respective commutator segment by engagingthe end of said one conductor in a slot in said one segment and then hotstaking the segment to connect the segment to the conductor.